How do I copy tracking data from one project to another?
You can't copy tracking data between points as the tracking data is unique to each point in the scene. You know as you drive along and everything moves at a different speed, the trees next to the road fly by while the mountains hardly move - camera tracking actually relies on that to calculate the location of the camera from the video.

There is nothing stopping you from adding another point and tracking that point. You also don't need to add another point just because you want to add an object next to something. The points that are reconstructed in the scene are for reference, if you have tracked post three and post five you can place an object in between and it will be next to post four whether there is a tracked point there or not.